class Animal:
    def eat(self):
        print("---吃---")

    def drink(self):
        print("---喝---")

    def sleep(self):
        print("---睡觉---")

    def run(self):
        print("---跑---")

class Dog(Animal):

    def bark(self):
        print("---汪汪叫---")

class Cat(Animal):
    def catch(self):
        print("---抓老鼠---")


a = Animal()
a.eat()

wangcai = Dog()
wangcai.eat()

tom = Cat()
tom.eat()
